Cooling device for hydraulic torque converters

ABSTRACT

A torque converter particularly adapted for automotive use is provided with novel and unitarily joined cooling means resulting in a more efficiently operating assembly.

United States Patent 1191 1111 ,82

Tokunaga July .16, 1974 COOLING DEVICE FOR HYDRAULIC [56] References Cited TORQUE CONVERTERS v UNITED STATES PATENTS [75] Inventor: Masayoshi Tokunaga, Osaka, Japan 2,216,747 10/1940 Klimek 416/180 2,428,728 10/1947 wt. 416/195 1 Asslgneei Kqbushlklcalsha Dalkl" 2,556,676 6/1951 Ca rri g ie 416/180 sa ush s a, Japan 2,692,560 10 1954 Zeider 415/175 2,745,354 5/1956 English et a1. 416/180 [22] Sept 1973 3,101,672 8/1963 Peras 416/180 [21] Appl. No.1 393,815

Primary ExaminerEverette A. Powell, Jr. [30] Foreign Application Priority Data Attorney, Agent, or FirmPierce, Scheffler & Parker Sept. 11, 1972 Japan 47-91612 57 ABSTRACT [52] U S Cl 1 416/180 416/95 A torque converter particularly adapted for automo- [511 'h'ig 6 d /04 tive use is provided with novel and unitarily joined 58] Fie'ld 418/95 b, 415/175, cooling means resulting in a more efficiently operating 29/154 FC assembly, I

4 Claims, 4 Drawing F igures- 2a 48 24 47 ix 44 [I i x 46 i 17 av i 1 A 2? x 42 38 0 2 J I 1 1 2o 34 3a a1 32 36 PATENTED JUU 6974 SNEET 2 [If 2 FIG-4 FIG.3

COOLING DEVICE FOR HYDRAULIC TORQUE CONVERTERS This invention relates to a novel cooling device for hydraulic torque converters.

It is well known that torque converters, and particularly those forming part of the driving assembly of automotive vehicles, are inherently subject to undesirable heating during operation. In torque converters, the working fluid is compressed, forced to flow rapidly and transmit considerable amounts of energy during operation. It therefore follows that the internal friction of the fluid causes a sharp temperature rise which results in deterioration of the fluid performance. Prior efforts to dissipate this heat has not been satisfactory. Also these structures have been so expensive to assemble as to increase excessively the cost of torque converters. For example, a prior type cooling device comprises a multiplicity of separate thin fins or other blade like members, each fin being secured individually on and projecting from the exterior surface of the impeller shell. In mounting these fins, a position setting jig is used to hold the fins relative to one another and to the impeller shell. Besides, the number of welding points increases, requiring considerable time, labor and expense. Also this structure is unsatisfactory since there is a tendency for the fins to loosen with attendent noise and rattle during the operation of the torque converter.

Another example ofthe prior art is shown in US. Pat. No. 2,692,560. In the patent, an annular blower shell made of light sheet metal in a one piece stamping is employed. The blower shell is attached with a little clearance over the exterior surface of the impeller shell and its radial embossments serve as fins as well as members to connect the blower shell on to the impeller shell. Although the air flows along the exterior surface of the impeller shell, a sufficient cooling capacity is not obtained by the device shown in the patent.

The present invention avoids the above discussed disadvantages. A principal object of the invention is to provide an improved cooling device having many radial ribbed blades connected by one or more annular ribs to form a unitary structure which is secured on the exterior surface of the impeller shell to not only increase the heat radiation capacity but to produce a composite structure of greater rigidity and durability.

Another object of the invention isto provide a cooling structure of greatly increased demension stability so that the blades will not loosen, the distance between the blades will not change with use time and the profile of a blade will not change, because each blade is strengthened and reenforced by the radial rib and preferably is integral therewith, preferably being stamped in one piece from sheet metal.

A further object of the invention is to provide a cooling device which simplifies assembly since a position setting jig is not necessary therein, permitting a lower cost of manufacture.

Other objects of the invention will be apparent from the following description taken together with the accompanying drawing, in which:

FIG. 1 is a sectional view of an upper half of a torque converter according to the present invention;

FIG. 2 is a perspective view taken from inside of the fin embodying principles of the invention;

In FIG. 1, reference numeral generally indicates a torque converter. Torque converter 10 comprises a drive impeller wheel (i.e., an impeller) 11; a driven impeller wheel (i.e., a turbine) 12; and a stator 13; the drive impeller wheel 11 being adapted to transmit energy to an inner working fluid, and in turn turbine 12 receives energy from such fluid. Stator 13 is fixed below a predetermined output-input speed ratio, to change the direction of the fluid to convert the energy thereof.

Impeller 11 is connected to an engine flywheel 14 to which the outer periphery of drive plate 15 is secured by bolts 16 and the inner part of the drive plate is secured by bolts 17 to a hub 18 and support ring 19. An axle 20 of the hub 18 is journaled in flywheel 14 by a bearing 21. A drive plate 22 is secured to support ring 19 as by weld 23 and a support ring 25 is also secured thereto as by weld 24. Around support ring 25 is a support ring 27 which is fastened to support ring 25 by bolts 26 and a liquid tight seal is provided therebetween by seal ring 28. I

Turbine 12 is fixed on a spline hub 20 by means of rivets 29, and, in turn, this hub 30 engages with a spline 32 on a driven shaft (i.e. a turbine shaft) 31. Turbine shaft 31 is journaled on a bearing 33 mounted inside hub 18 and support ring 19. A ring 34 prevents the shaft 31 from slipping off axially.

Stator preferably is cast in one piece, and is journaled on a fixed sleeve 35 through a one-way clutch 36, which includes an outer race 37 which engages with stator 13 through spline 38. Thus, as is well known in the art, during the accelerating process of converting torque up to a predetermined output/input velocity ratio, stator is fixed on a stationary sleeve 35, while at a velocity above said velocity ratio, the stator is free to rotate in the same direction as that of driven impeller wheel or turbine 12, to make the converter act as a fluid coupling.

The shell 39 of impeller 11 is stamped from a heavy steel plate, and has a semi-toroidal inner surface. An'

annular part 40 of shell 39 is secured to support ring 27 as by welded joint 40' and a part 41 of shell 39 is secured to'an impeller hub 42 as by welded joint 41'. A stamped cooling fin 43 is secured to the exterior surface of shell 39 as by welding.

As was already explained, during the operation of torque converters considerable heat is generated due to the rapid rotation of the moving parts thereof and the conversion of considerable amounts of energy, and this is particularly true of the impeller assembly. The cooling fin 43 radiates the heat effectively in the present invention.

The cooling fin, as shown in FIG. 2, is a unitary structure comprising a multiplicity of blades 44, each of which blades has a radial rib 45 connected at its inner end with an inner annular member 46 and at its outer end with an outer annular member 47 to form a strong and structurally rigid member. Each of ribs 45, 46, 47 has a configuration complementary to that of the exterior surface of shell to provide a snug fit therebetween as shown in FIG. 1. In FIG. 2, marks X indicate places where spot welding is applied. In the illustrated exampie, each radial rib 45 has one mark X, and inner and outer annular members 46, 47 have four and eight marks respectively. Spot welded portions are shown as at 48 in FIG. 1.

As shown, each blade 44 stands at the edge of radial rib 45 forming therewith an L section and has an even height from the exterior surface of radial rib 45, see FIGS. 3 and 4. Thus the radial rib 45 reenforces and materially increases the strength of ribbed blade 44, Le, the radial rib 45 holds the blade 44 rigidly along its entire root portion and acts to connect the blade 44 to shell 39. Inner and outer annular members connect and keep ribbed blades in fixed predetermined position. Accordingly, the blades will not loosen as use time passes thereby preventing noise and separation of the blades.

The fin 43 shown inFlG. 2 may be manufactured by the process comprising; press forming an annular depression on a steel plate having a thickness of 0.8 to 1.0 mm, which depression has a configuration complementary to that of the exterior surface of shell 39, cutting three rims 44a, 44b, 44c of the blade 44 and simultaneously bending the blade, and cutting off the inner and outer parts leaving inner and outer annular members 46, 47 behind. I

When assembling fin 43 and shell 39, fin 43 is simply placed on shell 39, and the position of fin 43 is automatically set. Then the two parts are spot welded as at points X indicated in FIG. 2 without the necessity for position setting jigs.

During operation, fin 43 dissipates the heat of impeller 11 through blades 44 which conduct the heat away from shell 39 and transmit it to the air flow generated by blades 44.

Spiral blades (not shown) may be employed instead of radially straight blades 44. In that case, the cooling device forms a high efficiency, open type centrifugal blower and smooth air flow may be obtained.

If the span of blades 44 is not large, one of the inner or outer annular members 46, 47 may be eliminated.

it is to be understood that this invention is not limited to the specific examples herein shown and described, but that changes and modifications may be made without departing from the spirit and scope of the invention, as defined in the appended claims.

I claim:

1. A cooling device for a hydraulic torque converter including an impeller shell comprising a plurality of ribbed blades and at least one of inner and outer annular members, each of said blades having a radial rib forming apart thereof, said ribs being connected to said annular members to form a unitary structure, each of said radial ribs and said annular members having a configuration complementary to that of the exterior surface'of said impeller shell, means for securing said unitary structure to the exterior surface of said impeller shell.

2. A cooling device according to claim 1, in which said ribbed blades and said annular members are formed in a one stamping.

3. A cooling device according to claim 1, in which said ribbed blades are connected to both said inner and outer annular members.

4. A cooling device according to claim 1, in which each of said ribbed blades is spiral. 

1. A cooling device for a hydraulic torque converter including an impeller shell comprising a plurality of ribbed blades and at least one of inner and outer annular members, each of said blades having a radial rib forming apart thereof, said ribs being connected to said annular members to form a unitary structure, each of said radial ribs and said annular members having a configuration complementary to that of the exterior surface of said impeller shell, means for securing said unitary structure to the exterior surface of said impeller shell.
 2. A cooling device according to claim 1, in which said ribbed blades and said annular members are formed in a one stamping.
 3. A cooling device according to claim 1, in which said ribbed blades are connected to both said inner and outer annular members.
 4. A cooling device according to claim 1, in which each of said ribbed blades is spiral. 